Leave it to the Bush administration to throw thousands of law-abiding American workers and companies off a cliff in perilous economic times.

That would be the effect of its decision to press ahead with a bad idea: to force businesses to fire employees whose names don't match the Social Security database. The purge is part of a campaign — along with scattershot workplace raids and the partial border fence — to make a show of tackling the broken immigration system.

The plan rests on the assumption that people with Social Security glitches are illegal immigrants using fake identities. Companies that receive "no match" letters warning of database discrepancies are given 90 days to clear them up. After that, they must fire the affected workers or face stiff penalties.

A federal judge blocked the plan last year, warning that it would create havoc in the economy and lead to serious due-process violations for victims of clerical errors. The Social Security Administration's inspector general has estimated that about 17.8 million of the agency's 435 million records contain errors that could lead to a "no match" letter. Seventy percent of those 17.8 million records belong to native-born Americans.

The Department of Homeland Security responded to the judge's objections by resubmitting its proposal last week essentially unchanged. Americans anxious about keeping their jobs should raise a stink and hope that the court rebuffs the agency again.

The Social Security Administration was set up to administer benefits, not to enforce immigration laws. There are many illegal immigrants who use fake IDs, but the sheer abundance of errors — the result of name changes, misspellings and other mix-ups — preclude their use for an immigration crackdown. Native-born workers will pay the price for these mistakes, but the foreign born also will suffer, because they are especially at risk of errors from inconsistent spellings, mistranslations and other language issues.

The plaintiffs in the lawsuit have warned, with good reason, that a Social Security crackdown would lead to countless unjust firings and discrimination against lawful immigrants by companies that cannot be bothered to help clear up their bureaucratic entanglements.

The burden on law-abiding companies would be great: thousands of dollars to comply with the rules, and thousands more to fire and replace workers. An honest employer who does things by the book would face an excruciating choice — to keep good workers despite dubious "no-match" letters and face harsh fines, or to fire them and face discrimination lawsuits.

All this churning, meanwhile, will be a boon for the unscrupulous businesses that hire off the books and have no use for W-2s. It's a law-and-order strategy that undermines law and order.